Skip to main content

Full text of "Bird Genealogy"

See other formats


STOP 



Early Journal Content on JSTOR, Free to Anyone in the World 

This article is one of nearly 500,000 scholarly works digitized and made freely available to everyone in 
the world by JSTOR. 

Known as the Early Journal Content, this set of works include research articles, news, letters, and other 
writings published in more than 200 of the oldest leading academic journals. The works date from the 
mid-seventeenth to the early twentieth centuries. 

We encourage people to read and share the Early Journal Content openly and to tell others that this 
resource exists. People may post this content online or redistribute in any way for non-commercial 
purposes. 

Read more about Early Journal Content at http://about.jstor.org/participate-jstor/individuals/early- 
journal-content . 



JSTOR is a digital library of academic journals, books, and primary source objects. JSTOR helps people 
discover, use, and build upon a wide range of content through a powerful research and teaching 
platform, and preserves this content for future generations. JSTOR is part of ITHAKA, a not-for-profit 
organization that also includes Ithaka S+R and Portico. For more information about JSTOR, please 
contact support@jstor.org. 



THE AUK: 

A QUARTERLY JOURNAL OF 
ORNITHOLOGY. 

Vol. xxix. July, 1912. No. 3. 

BIRD GENEALOGY. 1 

BY CHARLES W. TOWNSEND, M. D. 

Arceleopteryx had teeth in its jaws, separate hip bones, bi- 
concave vertebrfe, claws on its front limbs and a vertebrated tail, 
all marks of the reptile, in which group it might still be placed 
by some, were it not for the fact that the impression of the 
feathers has been preserved to us and stamps its essential bird 
nature. The links between birds and their reptilian predecessors 
are very perfect. 

Now if birds are descended from reptiles, one may perhaps still 
find some traces of this lowly origin in the infantile period of bird 
life, just as there are various ear-marks of the savage of the jungle 
in the infancy of the most gilded city dweller, not to mention the 
transient and permanent reversions often found among adults of 
the race. Thus the Hoatzin of the Orinoco when young, has 
claws on the wings and scrambles about the branches in a truly 
reptilian style, a mode of progression that, according to Beebe, is 
still used by the adults. 

One need not go so far as the Orinoco, however, to find evidences 
of the quadrupedal reptilian mode of progression in birds, as 
witness the actions of young Herons before they learn to fly, when 
with wings and legs they climb about their family tree almost as 
gracefully, I dare say, as did some of the ancient winged reptiles. 

• Read before the Nuttall Ornithological Club, March 4, 1912. 

285 



286 Townsend, Bird Genealogy. [j u i y 

The extension of the so-called thumb or bastard wing in the Pigeon 
and other birds as they approach their perch may in the same way 
hark back to the time when the reptilian ancestor grasped with its 
fore feet its goal on the tree tops. Both young Green and Night 
Herons elevate the bastard wing at times as they climb about the 
trees, but I have never seen them attempt to use it for grasping. 

Left with a couple of young English Sparrows on my hands 
owing to the destruction of their nest caused by the closing of a 
blind, I dropped them into a basin of tepid water, expecting the 
inert masses to sink or at least that their wabbly heads would fall 
below the surface. On the contrary they became endowed with 
life and vigor as if upon their native heath, and, with a combination 
of rapid wing strokes and leg action, and with necks outstretched 
they scudded across the surface of the miniature pond. 

Blood will out, the reptilian ancestry was working! To make 
sure that this was not an accident I dropped a young Red-winged 
Blackbird into the pool below his nest. He too performed in ex- 
actly the same manner and safely reached some reeds up which he 
scrambled, and was there well taken care of by his excited parents. 
It is probable that many a passerine bird nesting over the water 
has been saved from destruction by this return to primitive methods. 

Further experimentation with young Crows and Bronzed Grack- 
les showed me that very young birds generally moved the wings 
alternately, while older ones always napped both together as in 
flight. From this one would infer that the primitive reptilian 
scramble was naturally an alternate method while the simultaneous 
method was simply the more advanced style used in flight. 

In the case of the Chimney Swift the method of flight has been 
thought to be an alternate flapping of the wings. Let anyone 
watch these curious birds as they dart with amazing speed through 
the air, and I am sure he will agree that the wings are used alter- 
nately with great rapidity. Steady flight by this method is, I 
believe, mechanically possible. One might argue therefore that the 
Swifts retain the more primitive or reptilian method of moving 
the front limbs and are therefore members of a very early branch 
on the avian tree, although it is possible that through extreme 
specialization they have returned to this form of flight. 

If this prone method of propulsion on the water on all fours is a 



° 1912 J Townsend, Bird Genealogy. 287 

primitive one, as indeed it must be, then birds that swim in an 
erect Duck-like manner must have advanced beyond this stage 
and become specialized. I have several times seen young Spotted 
Sandpipers that were unable to fly, swim with ease like little 
Ducks, although when very young and much frightened they 
return to the primitive reptilian scramble on all fours. All of 
the members of the Shore Bird family swim naturally if they find 
themselves in water beyond their depths. Phalaropes habitually 
disport themselves on the surface of the water as gracefully as 
miniature Swans. It would seem to be a natural inference, there- 
fore, that the ancestors of Shore Birds were swimmers and that 
the art of swimming is inherited and not developed by this group, 
and that the Phalarope is a case of reversion. The awkward 
action of a young seal at its first bath is an example of a case where 
the art of swimming has been recently acquired by a group and 
where it is not one of long inheritance. 

In the classification of birds proposed by Hans Gadow the order 
Charadriiformes, or Plover-like birds, includes the Shore Birds, 
Gulls, Auks and Pigeons. The Shore Birds, we have just seen, 
show evidence of a swimming ancestry, although, with the excep- 
tion of the Phalaropes, they habitually prefer the shore under their 
feet, even if it is wet and partly covered with water, to the deep 
sea. The presence of partial webs, as in the Willet and in the 
Semipalmated Plover and Sandpiper, point to the former existence 
of the swimming habit, for these birds like other Shore Birds do 
not swim except when unexpectedly forced to it. 

If the partial web in the foot of the adult Shore Bird showed the 
beginning of the swimming habit in birds of land ancestry we 
should find the young birds like young seals very inexpert in the 
water. As the reverse of this is the case our conclusion that 
these birds are of water ancestry must be correct. 

Gulls and Terns have fully webbed feet but their habits at the 
present day hardly justify them in this possession. Webbed feet 
are of great advantage to the rapidly swimming bird and to the 
diving bird that depends on its feet. Now Terns rarely rest on the 
water or swim and Gulls do not often swim rapidly, in fact they 
rarely swim at all, but drift about, while if either bird descends 
below the surface, it is as a result of the velocity of its plunge from 



288 Townsend, Bird Genealogy. [j u i y 

the air, and its feet are probably not used. In fact the web, 
although useful, is largely wasted on these birds, and it is evident 
that it is ancient and points to a swimming ancestry. That this 
ancestry is less remote than in the Shore Birds is perhaps shown 
by the fact that a wing-tipped Gull, falling on the beach will take to 
the water, and swim vigorously out to sea, while a similarly crippled 
Shore Bird falling into the water will swim to the beach and endea- 
vor to run inland to hide. 

Before they are able to fly, young Skimmers are said to seek 
safety by running into the water, another evidence of their water 
ancestry. Chapman in his " Camps and Cruises of an Ornitholo- 
gist," speaking of young Common Terns a few days old, says: 
"several were seen to enter an inflowing creek, drink repeatedly 
of the salt water and swim actively, in evident enjoyment of their 
natatorial powers, while the parents, who rarely alight on the water, 
watched them from the shore. Possibly here was an explanation 
of the value to Terns of webbed toes. Functionless in the adult 
they are of service to the young, before the power of flight is ac- 
quired." In this supposition he is probably right, although this 
service to the young is not the reason for the existence of the webs, 
but the observation points very clearly to the swimming ancestry 
of the birds. We could not have stronger proof of it. 

That the Auks are out and out water birds there needs no defence, 
but one is at first sight puzzled by the presence of the Pigeons in 
this group. The older systematists placed the Pigeons with the 
Partridge and Domestic Fowl tribe, but Pigeons may be seen 
wading in puddles in a manner that would alarm the Barnyard 
Cock. I have been told by a Pigeon fancier that young Pigeons 
are much attracted by water, and fond of bathing therein, and 
that young birds are liable to drown themselves in tanks or troughs 
if these are accessible to Pigeon lofts. I recently placed a half- 
grown Domestic Pigeon in a wash-tub of tepid water. With head 
and neck erect, the bird swam rapidly with alternate strokes of the 
feet to the side of the tub. The wings were arched up and waved 
slightly, — not stretched out and flapped in the water as in the 
case of young Passerine birds. Its position was like that of a 
Duck but low in the water. Progress was much more rapid than 
on land where the bird stumbled awkwardly along. Indeed it had 



'i9i2 J Townsend, Bird Genealogy. 289 

never before left the nest. I repeated the experiment several 
times with the same result. A fact of considerable interest in this 
connection is that "A Pigeon with a perfectly webbed foot [was] 
evolved at Cambridge by only three years' selected crossings." 1 
This may be looked upon as a case of reversion. The throwing 
of somersaults in the air similar to those of the Tumbler Pigeon 
has been reported in the case of the Black-bellied Plover. 

The Sheathbill, Chionis, is so ancestral and generalized in its 
type that it suggests all the groups we have just been considering. 
Anatomically it is allied to the Oyster-catchers and the Gulls. It 
is often classed among the Plovers, but it is as marine in its haunts 
as are the Auks, and in flight it resembles the Gulls. Its appearance 
on land, gait and manner of courting are very much like those of 
a Pigeon, and it goes by the name of ' Kelp Pigeon.' 

While young Terns take to the water, young Cormorants when 
pursued take to the shore. This would suggest a terrestrial an- 
cestry of these birds, and according to Gadow, Cormorants strik- 
ingly resemble the New World Vultures, and the habit of both 
these birds of sitting with their wings spread is suggestive of 
kinship. The fact that Cormorants on rising into the air hop with 
the feet together, although their usual gait is a waddle, suggests 
a former arboreal life, and many Cormorants still nest in trees. 

Tree dwellers naturally hop from branch to branch, and it is 
probable that the earliest birds were arboreal. When the tree- 
dwelling bird descends to the ground it naturally hops there also, 
but hopping is not a satisfactory method of progression for a 
ground-feeder, — it does not permit of cautious approach, and it is 
decidedly jarring. A walking gait, therefore, may be understood 
to indicate a long custom of feeding or dwelling on the ground. 
Although the Flicker is frequently seen on the ground, the ground 
habit is probably but recently acquired, for it has not learned to 
walk, while the Robin for example is able to run, and does so much 
more often than it hops. Young Robins show, however, their 
arboreal ancestry by hopping more than they run. Pipits, Horned 
Larks and Ipswich Sparrows have so completely departed from 
arboreal habits, that they run easily and walk with grace. Walking 

1 T. Digby Plgoit, "London Birds and other Sketches". London. 1902, p. 239. 



290 Townsend, Bird Genealogy. [july 

appears to be acquired later than running. It is a very interesting 
fact that the Savannah Sparrow, frequenter of meadows and 
marshy pastures, generally hops even when on smooth ground, 
although it is also a good runner, while its near relation the Ipswich 
Sparrow, frequenter of sandy wastes, almost never hops and is a 
good walker. 

Herons as far as I know, although constantly in the water very 
rarely swim, but that they come of a swimming ancestry seems 
probable from the behavior of a young Green Heron not old enough 
to fly that I put in the water. It sat erect on the surface and swam 
off with a grace and ease that contrasted forcibly with its awkward 
movements on land. Not only was its poise graceful and Swan- 
like, but the speed with which it swam, the practiced manner in 
which it feathered its ungainly toes, the ease with which it threaded 
its way among the grass stalks, and dabbed every now and then 
at the water with its bill, all pointed to an inherited instinct, an 
instinct, however, that is largely if not entirely lost in adult life. 
This young Heron had never practiced the art of swimming before 
— it had probably never left the nesting tree, which was on a 
marsh island some distance from even the highest tides. Adult 
Herons like some Shore Birds show their swimming ancestry by a 
distinct web between the middle and outer toes. 

The use of the wings under water in some diving birds and the 
significance of this fact I have already discussed in another place. 1 

One is apt to think of evolution as a thing of the past, an ac- 
complished fact, and to forget that at the present period of time 
this great law is still as existent as it has been since the world 
began. With change in environment, there comes through natural 
selection acting on slight variations and occasional mutations a 
change in the structure to fit the new environment, and in time 
a new species is developed. As new species arose in the past, so 
they must be in various stages of formation at the present time. 
The great group of American Warblers are for the most part slender- 
billed, insect-eating birds, that go south with the approach of cold 
weather. One of them, however, is enabled to spend the winter 
on the bleak New England coast by a change from an insectiv- 

» Auk, XXVI, 1909, pp. 234 to 248. 



V0l 'i9i? IX ] Townsbnd, Bird Genealogy. 291 

orous to a seed-eating habit. The Myrtle Warbler thrives through 
the cold winters chiefly on a diet of bayberries, while all the other 
members of this family seek more genial climes, where they may 
continue to live on insects. Not only this, but a large number 
of its own species go south, and winter in the Greater Antilles, 
Mexico and Panama, where insect food is of course abundant. 
The New England birds eat not only bayberries, but also the seeds 
of grass and weeds that extend above the snow, and they glean 
the bark of trees like Titmice. 

Now birds like men are clannish; in fact there is a remarkable 
similarity between animal and human nature, — which is not so 
surprising when one considers our origin and relationships. Among 
savages slight differences due to different environment, set apart 
one group or race from another. Each race considers itself the 
people, and despises, fights and refuses to mix with the other. The 
Eskimo and the Indian, although both manifestly of Eastern 
origin, so dislike each other that intermarriage, except under the 
influence of civilization, is rare. This tendency makes of course 
for differentiation; without this tendency the constant mixture 
of races would make the production of new species more difficult. 
While this clannishness is most marked among savages, it is also 
so pronounced in civilized races that each nation classes all foreign- 
ers, especially those that speak a different tongue, as their inferiors 
with whom intermarriage is not to be thought of. The more 
ignorant the individuals, that is to say the more primitive or 
animal-like, the more intense is this clannishness, and, its boun- 
daries may be limited, not by the nation or state, but even by the 
village in which the individuals live. Mr. Punch's collier who 
proposed ' leaving 'alf a brick' at the stranger in town is an in- 
stance in point. 

The element of home also enters into this exclusiveness which 
favors the formation of races, and hence of new species. This 
factor is strongly shown in the human species unless the individual 
has become cosmopolitan by travel and education; and the in- 
habitants of what appears to an outsider to be a most desolate 
region regard their home as superior to any other country on the 
globe, and pine if taken away from it. 

Now the seed-eating Myrtle Warbler that spends its winters 
in the cold and stormy north is undoubtedly as clannish as the 



292 Townsend, Bird Genealogy. uvly 

Eskimo, and considers itself superior to the south-seeking Myrtle 
Warbler, and it would probably pine for its northern home if 
transplanted by force with the rest of the species to tropical regions. 
In addition, its clannishness probably impels it to chose a summer 
home apart from its southern relations. 

At present man cannot distinguish the northern from the 
southern Myrtle Warbler, just as in the remote past, it is probable 
that the Eskimo could not be distinguished from the Indian. In 
time, however, aided by this inherent clannishness and love of 
home, one might predict that a larger race of northern Myrtle 
Warblers would be formed with thicker, stronger bills and more 
muscular gizzards. Indeed I have endeavored to investigate these 
three points in order to discover whether a beginning had been 
made in the evolution of this new species, but I have not as yet 
examined enough material to throw any light on the subject. 

One can easily see how important the element of clannishness is, 
for without it interbreeding might for a long time, if not indefinitely 
delay the birth of a new species. The importance of clannishness 
in the evolution of races and species, has I believe never been given 
due weight. 

As among men so among birds there are striking differences in 
ambition and ability to succeed. Some men, some families, some 
nations are progressive, — they are always reaching out for new 
opportunities and taking advantage of them. Others are retiring, 
unambitious and contented to remain where they are. One of the 
most remarkably progressive birds is the Horned Lark which has 
spread to nearly every part of the continent, and has made each 
part so much its home that it has adapted itself to the environment 
to the extent of changing its own form and plumage. There are 
now recognized fourteen different North American races or sub- 
species of the Horned Lark. The pushing character of the bird 
is shown in the recent extension of the breeding range of the 
Prairie Horned Lark from the central part of the continent to New 
England. In 1889 it was first recorded as breeding in Vermont, 
and the same year in central Massachusetts. In 1903 it reached 
the sea and bred at Ipswich and has come there to raise its young 
ever since, meanwhile increasing in numbers throughout the New 
England states. 1 

> Auk, XXr, 1904, p. 81. 



V ° 1 'i9i2 aX ] Townsend, Bird Genealogy. 293 

The Song Sparrow has adapted itself in twenty different forms 
to all parts of the continent, and is abundant almost everywhere. 
Incidentally it is interesting to compare a map of North America 
showing the various lingual races of Indians with one showing the 
various races of Song Sparrows. Both maps show an extensive 
race in the more uniform east — the Algonquin Indians, and the 
melodia sparrow, — while both show in the diversified surface of 
the extreme West numerous races of both man and bird. 

What a contrast is the enterprise shown by the Song Sparrow 
to the lack of enterprise in the case of such a bird as the Swamp 
Sparrow, for instance. Although first cousin to the Song Sparrow 
and although it is spread over a large territory, the Swamp Sparrow 
limits itself to the almost uniform environment of swamps, and 
has therefore never developed any races. 

Another bird which is showing great developmental or evolution- 
ary possibilities is the Grackle both Purple and Bronzed. This 
bird instead of shunning man has beeij bright enough to appreciate 
the fact that it is safest from persecution when in most intimate 
relations with him. It has come into his towns and cities, and it 
does not hesitate to build its nests on his houses. In Boston, 
although there had been a few previous records, it was not until 
1900 that the Bronzed Grackle began to breed regularly in the 
Public Garden, and the numbers increased so that thirty-two nests 
were counted there by Mr. H. W. Wright in 1906. In 1907 they 
first began to build nests in the vines on my Ipswich house, and 
two pair have nested there every summer since, when I permitted. 
In the matter of food they are not particular, or rather their 
appetite is a catholic one, and they can adapt themselves to cir- 
cumstances. They are able to pick eggs out of a Robin's nest and 
peas from pods in the garden, and they undoubtedly serve a useful 
purpose in towns and cities by diminishing the English Sparrow 
nuisance. I have seen one hold down a struggling English Sparrow 
with its foot while it deliberately pecked out its brains. While 
the English Sparrows follow Robins hunting worms on the lawn, 
and saucily snatch the worm away from their very mouths, they 
keep at a safe distance from the Grackle, and if he so much as 
stops to look at them, they fly off in terror. In fact Grackles put 
to flight the innocent Robins. I have seen a Grackle partly run 



294 Townsend, Bird Genealogy. [july 

and partly hop with wings extended toward a Robin that was 
digging worms near by, making the Robin desert the spot on which 
the Grackle then dug. 

But the most interesting development of the Grackle, one that 
shows its great adaptability and intelligence, is a habit it has of 
picking up food from the water, after the manner of the Herring 
Gull. A Grackle will hover close to the water its head to the wind, 
and then suddenly drop, and with its bill pick up from the surface 
some morsel as gracefully as a Gull. This they do at times with- 
out wetting their plumage; at other times the bill, feet and tail 
are immersed, while I once saw a Grackle splash his whole body 
into the water and entirely immerse his head, to emerge without 
difficulty, carrying in his bill what appeared to be a small silvery 
fish. I have seen them after sailing and hovering over the water 
in a high wind with the spray dashing about them, skilfully pick 
up food from the tops of the waves. 

It is easy to picture an island community of Grackles becoming 
more and more addicted to a maritime life, owing perhaps to the 
shrinking of their terrestrial food supply due to a change of climate 
or to land subsidence. Would not these habits become in time 
as much inherited as are similar habits in the Gulls? Or, to put 
the question in another way, were not the inherited traits of the 
Gulls originally acquired? 

The Ipswich Sparrow is the only strictly dune dweller among the 
birds. Its summer home is on Sable Island, an island of sand dunes 
off Nova Scotia, and it spends its winters along the sandy portions 
of the Atlantic coast. It is evidently a near relation of the Savan- 
nah Sparrow, which is somewhat smaller and darker, and lives 
chiefly in marshes and open fields from Labrador to New Jersey. 
As the glaciers receded we can picture the gradual pushing north 
of the Savannah Sparrows, and their extension to the great sandy 
wastes that fringed the coast for miles. As the land sank and the 
waters rose restricting these regions of sand, the struggle for life 
among the clan that preferred the sand dunes must have been an 
intense one, and it is probable that the larger and stronger birds, 
as well as those that more nearly matched in color their surround- 
ings were the more likely to survive. Isolation from the main 
land finally aided in the work, and at last a distinctly new species 



V ° I 'i9i2 aX ] Phillips, The American Black Ducks. 295 

was evolved, a bird larger than the Savannah Sparrow of the main 
land, and of a gray or sandy, rather than a black and brown color, 
so that when it squatted in terror on the sand the sailing Hawk 
was more apt to pass it by. 

It seems to me, therefore, that the evolution of the Ipswich 
Sparrow is comparatively recent, and that the age of this species 
may be counted by the paltry fifty thousand years or so that have 
elapsed since the last glacial period. 



A RECONSIDERATION OF THE AMERICAN BLACK 

DUCKS WITH SPECIAL REFERENCE TO 

CERTAIN VARIATIONS. 

BY JOHN C. PHILLIPS. 

There are several species of primitive ducks which for many 
reasons are of peculiar interest, on account of their remarkable 
geographical distribution and mutual interrelationship. This 
group of species is composed of Anas fulvigula, Anas tristis, Anas 
diazi, Anas wyvilliana and Anas laysanensis. Most of these are 
poorly represented in collections and this fact has led to certain 
misconceptions. It is the purpose of the following notes to point 
out some of these mistakes, and to say a few words about individual 
and sexual variation. 

To begin with I wish to call attention to the principal difficulty 
in the proper understanding of these local races; this is the presence 
of a sexual difference in plumage, increasing probably with age, 
and comparable, with that of the Hawaiian duck (Anas wyvilliana). 
In this way all these related species can be separated from A. 
tristis in which the sexes are similar. At first I thought that this 
sex difference was confined to A. diazi and I started to limit these 
notes to the latter species, but as more specimens turned up I 
thought it better to consider all the American Black Ducks.